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At the synthesis temperature of α-cordierite (α-Mg 2 Al 4 Si 5 O 18), compositions of Mg 2+ x Al 4-2 x Si 5+ x O 18 crystallized as β-cordierite (β-Mg 2+ x Al 4-2 x Si 5+ x O 18) when x is over 0.2. By doping Eu2+ into optimal host β-Mg 2.25 Al 3·5 Si 5·25 O 18 (β-MASO), a series of novel cyan luminescence materials were obtained. Excitation spectra ranged from 250 to 450 nm, and peaked around 365 nm. Under wavelength of excitation peaks, emission maximum of series samples moves from 464 nm to 485 nm with the increase of Eu2+. Decay behaviors and Gaussian multiple fitting results of emission spectrum, consistent with crystal analysis that the Eu2+ occupy three kinds of crystallographic sites. For representative sample β-MASO:0.02Eu2+, internal quantum efficiencies (η 1) is about ∼56.96%, and its emission intensity remains at 66% of initial intensity at 150 °C. Under excitation at UV (365 nm) lamp, the white light with warm tune was obtained by mixing β-MASO:0.02Eu2+ with red CaAlSiN 3 :Eu2+. The electro-luminescence spectrum mainly distributes in blue (400–520 nm) and red (600–740 nm) regions and overlap with main absorption zone of plants. [Display omitted] • At the synthesis temperature of α-cordierite, Mg 2+ x Al 4-2 x Si 5+ x O 18 crystallized as β-cordierite (β-Mg 2+ x Al 4-2 x Si 5+ x O 18).. • A novel cyan-emitting β-Mg 2.25 Al 3·5 Si 5·25 O 18 :Eu2+ were synthesized. • The synthesized green phosphor is suitable for plant growth. [ABSTRACT FROM AUTHOR]

Novel Ca 1.96 (B 1- y Si y)(O 3- y N y)Cl:0.04Eu2+ phosphors were designed and synthesized by introducing [Si4++N3−]/[B3++O2−] co-substitutions into Ca 2 BO 3 Cl:Eu2+ lattice. Fourier Transform Infrared Spectroscopy (FTIR) show that typical planar [BO 3 ]3− units gradually transformed into [BO 4 ]5− units with the increase of y , which was firstly realized in luminescence materials. Uneven expansion of cell parameters a,b, and c were confirmed by the combination of X-ray diffraction spectra (XRD) and results of Rietveld refinement. Structure variation caused smaller centroid shift (ε c) and 5 d energy level splitting (ε cfs), inducing the narrowing of excitation spectra (y = 0 → y = 0.2, 168 → 144 nm) and blue-shift of emission spectra (y = 0 → y = 0.2, 582 → 525 nm). Excellent thermal stability (6% loss at 150 °C) was obtained, which resulted from more covalent bonding. Using the combination of representative sample CBSOCN 0.2 : 0.04Eu2+ and red K 2 SiF 6 :Mn4+ in a blue LED driven lamp, white light with high CRI ~92.8 and color temperature closed to the summer sun (5770 K) was obtained. Unlabelled Image • [Si4++N3−]/[B3++O2−] co-substitution was applied to synthesize the Ca 2 (B 1- y Si y)(O 3- y N y)Cl:Eu2+ series. • Luminescence color change from yellow to green with the increase of y. • Thermal stability of samples increased with the increase of y. • White light with high CRI can be synthesized by using the optimal sample CBSOCN 0.2 : 0.04Eu2+. [ABSTRACT FROM AUTHOR]

The ability to manage reactive oxygen species (ROS) effectively is crucial for the survival of gut bifidobacteria under conditions of oxidative stress. Alkyl hydroperoxide reductase catalytic subunit C ( ahpC ) of Bifidobacterium longum responds to various oxidative stresses. In this study, an ahpC -overexpressing transformant of B. longum strain NCC2705 was constructed to investigate the role and function of ahpC in oxidative stresses inflicted by treatments with hydrogen peroxide (H 2 O 2 ), cumene hydroperoxide, and aerobic oxygen. Results indicated that in B. longum , AhpC is the primary scavenger of endogenous H 2 O 2 generated by aerobic metabolism, but it is unable to detoxify high concentrations of exogenous H 2 O 2 . The ahpC -overexpressing B. longum strain showed increased resistance to organic hydroperoxide killing, increased viability under aerobic growth, but decreased resistance to exogenous H 2 O 2 in comparison to the control strain. Analysis of genes from the oxidative stress-defense pathway encoding oxygen-independent coproporphyrinogen III oxidase ( HemN ), NADH oxidase ( Nox ) and thioredoxin reductase-like protein ( TrxB ) showed increased transcript levels in the ahpC -overexpressing vs. control strain. These findings suggest that elevated ahpC expression facilitates or activates the different electron donor-dependent ROS-elimination pathways in B. longum 's response to oxidative stress. [ABSTRACT FROM AUTHOR]